Jars are commonly employed to contain household materials, particularly food stuffs, for convenient storage and retrieval. Jars are usually equipped with thin metallic or plastic lids which attach to the jars by means of cooperating threads. It has been recognized by those skilled in the art that there are many instances where manual removal of a jar lid is either very difficult or not feasible. For example, a lid may be too tightly installed during the manufacturing process, making it difficult to remove. Fluid trapped between the threads may also cause the lid to stick in a tightened position.
In order to assist persons who for what ever reasons need such assistance in opening a jar, numerous machines for unscrewing lids from jars have been proposed in the prior art. These prior art machines usually include a base having a vertical shaft on which is mounted a gripping device for holding a jar by its lid. The gripping device is disposed above a second gripping device located on the base. The second gripping device is used for holding the jar. One of the gripping devices is provided with powered rotation means and the other gripping device is immobile. In operation, a torque provided by the rotation means is imparted to the jar in order to break a seal or initial resistance securing the lid to the jar.
Examples of prior art jar lid opening machines are described in U.S. Pat. No. 5,370,019, issued to Sartell et al. on Dec. 6, 1994, U.S. Pat. No. 5,617,765, issued to Bennett on Apr. 8, 1997, U.S. Pat. No. 6,125,718, issued to Hill on Oct. 3, 2000 and U.S. Pat. No. 6,182,534, issued Hardman on Feb. 6, 2001.
The prior art jar lid opening machines usually do not have a compact configuration because they must include two gripping devices which are disposed spaced apart. However, this configuration is necessary in the prior art jar lid opening machines in order to provide a fully automatic operation, considering the powerful torque provided by the machines needed to break the seal or initial resistance securing the lid to the jar. Therefore, it is desirable to develop an improved powered jar lid opener which is compact and convenient to use.